1. Field of the Invention
The present invention relates to an inflator for an air bag used in an air bag system of an automobile.
2. Description of the Related Art
A gas generator for an air bag inflator includes a type that mainly uses a pressurized gas as an air bag inflating medium, a type that uses only a solid gas generating agent (in which a gas is generated by combustion of the gas generating agent) and a type that uses both the pressurized gas and the solid gas generating agent. In order to simplify the assembly process of all of these types, there are demands for reductions in the number of components and simplification of the assembly operation.
In an inflator disclosed in JP-A No. 2003-11769, which uses a solid gas generating agent and a pressurized gas, a cup member is required to separate a space for charging the gas generating agent from the remaining space. In FIG. 1 of JP-A No. 2003-11769, for example, a cup member is used as a gas generating chamber housing 114, and the gas generating chamber housing 114 is welded to a boss 130 at 146. When this type of welding method is used, a large amount of equipment is required for the welding, and hence there is room for improvement in terms of simplifying the assembly process.